During the use of the radar antennas, the components in the electronic system of the radar antenna heats up and must be cooled not to be overheated. Electronic systems of radar antennas mounted on the body of an aircraft are, during flight, cooled by the airflow from the surrounding air. The electronic system is arranged within a housing, wherein the airflow is lead into the components of the electronic system through an air inlet and an air pipe. The electronic system of the radar antenna is thereby exposed to varied temperatures, wherein the lowest temperatures are below −55° C.
Due to the very low temperature caused by airflow, special designed components are used in the electronic system of the radar antenna. The special designed components can withstand lower temperatures than conventional industrial components; this makes the electronic system of the radar antenna more insensitive to low temperatures. For industrial components used today the critical temperature is normally at −40° C. The special designed components are supplied by just a few suppliers and are much more expensive than conventional components.
The electronic systems must not just be designed to be able to stand low temperatures; the same system is subjected to high temperatures, essentially because of the heating effect of the system itself. For electronic system with soldered components, the temperature can not be allowed to be raised above the critical temperature +85° C., because the soldered seems can start to degrade.